Petroleum depletion and environmental issues caused by the chemical and petrochemical industries have led to a renewal of interest for using biomass as a carbon source for biofuels production. Various research organizations including program offices within the United States Department of Energy have sought, and continue to seek, transformative and revolutionary sustainable bioenergy technologies. Ethanol conversion to biofuels is one of these attractive bioenergy technologies. Ethanol can be commercially produced at large scale from renewable biomass or waste sources, and continuing advancements in production efficiency and feedstock diversification are envisioned to lead to excess ethanol at competitive prices. The broad availability and cost effective supply of ethanol as a feed stock would enable the production of a wide range of fuels and commodity chemicals.
While ethanol supplies are predicted to rise, a reduction in supplies of other commodity chemicals is also expected. A variety of approaches have been taken attempting to identify simple and cost effective processes for generating desired fuels and commodity chemicals in newer, greener and more cost efficient ways. While a variety of processes have been shown to have some efficacy continued development is needed to find methods that can simply and cost effectively produce the desired result and do so in a sufficiently cost effective manner so as to be adopted in industrial and commercial applications. The present disclosure describes significant advances in this regard.
The following description provides examples and information surrounding successful demonstration of a proof of concept for single step conversion of (aqueous) ethanol into butenes, such as 1-butene. As will be explained below in further detail, oligomerization of mixed 1- and 2-butenes, produced by the single step methods described hereafter allow for the creation of various hydrocarbon fuel configurations both in the presence of and/or absence of hydrogen and/or ethylene.
By directly producing a C4-rich olefin mixture (that can then be selectively oligomerized into gasoline, jet and/or diesel fuels) from an ethanol containing steam various advantages are presented including, but not limited to, significant cost reduction in capital expenses and operational expenses as this simplified process allows for a closer term transformation of a feedstock to a useable product. In some embodiments the conversion of ethanol to butenes can be conducted one single reactor. In one arrangement, the present process was demonstrated using an aqueous ethanol feedstock indicating that typical ethanol/water separations may not always be necessary. This coupled with a reduction of stages in additional chemical processing and allows for various simplified operation units, which can present a significant step forward in reducing costs and complexities and moving renewable transportation fuels forward toward a practical reality.
Additional advantages and novel features of the present disclosure will be set forth as follows and will be readily apparent from the descriptions and demonstrations set forth herein. Accordingly, the following descriptions of the present disclosure should be seen as illustrative of the disclosure and not as limiting in any way.